The present invention relates to a computer controller for an industrial multiaxis robot, in which the motion of the robot tip given in stationary coordinates is transformed into corresponding reference values for the drives in the individual robot axes.
The tracing of linear tracks with orientation-following of a tool generally requires a six-axis robot. Controllers for such six-axis articulated robots with coordinate transformation are known (see, for instance, U.S. Pat. Nos. 3,909,600 or 3,920,972). In calculating the transformation values, it can happen for certain axis constellations that individual axes would have to assume very large acceleration and velocity values in order to maintain the prescribed track. The theoretical values so obtained can far exceed the permissible limit, be it because of the drives or on the part of mechanical safety. In order to avoid such overloads it would be conceivable, for instance, to design the controller in such a manner that the robot stops in these critical positions. Starting from a standstill so reported, another track would then have to be programmed. Another possibility would be to limit the determined reference values for velocity and acceleration. This, however, would have the result that the prescribed, for instance, straight-line track cannot be followed in many cases.